Looking for compatible rails

Hi all just bought my first rack it’s a Vevor 27u 4 post open rack

https://www.vevor.com/products/vevor-open-frame-server-rack-network-server-rack-27u-4-post-19-steel-relay-rack-1?variant=393726355047

But the issue having is finding rails that both fit my chassis and also for within the compatible specs for my rack (which is only 23") deep.

The chassis I have is a rose will lab 5400 which is 27" deep and the rails I first attempted to use were tbe official rose-will ones (which had I read the reviews o would have know , commonly don’t fit a lot of racks)

I then stumbled across the server-builds article/forum post about using the ISTAR TC-RAIL rails and that these usually work , but I’m struggling to find any that BOTH support my chassis of 27" deep and also support a rack that’s only 23" deep.

Should I go for the 20" version of the TC-RAIL , the 26"or the 20" version , I really have no clue.

Don’t bit my head off please I’m new to rack-mount stuff and this is my first crack at a he lab.

Thanks in advance.

MM